This invention relates to a method of cleaning cloth using pulsed microwave energy.
Machines which make use of microwave energy to clean and/or dry cloth are known in the art. Most of these machines focus on using microwaves to heat the water used during the cleaning process, thereby using less energy than machines that make use of, for example, heating elements. Machines which have a drying function focus on heating the water within the wet or damp cloth, speeding up the drying process.
Developments in this field of application, have been to positioning a microwave-generating device (the magnetron) within washing machines, as well as methods of directing microwaves to the desired objects, i.e., the water to be heated or the fabric to be dried. U.S. Pat. Nos. 4,356,640, 5,463,821 and 4,334,136 are examples in this regard.
An important piece of prior art in relation to the present invention is US Patent Application US2002/0062667, entitled “Method and apparatus for washing items having cloth with microwaves”. The specification teaches an apparatus that relies on continuous microwave irradiation onto wet cloth in order to agitate water and soap/detergent molecules within the cloth. The agitation comes about as a result of rotational motion of the molecules due to said microwave irradiation, the primary effect of which is the enhanced cleaning effect of water and detergent. A secondary effect of such irradiation is an increase in temperature of the water itself.
A drawback of the apparatus is discovered upon practical use thereof. The microwave energy that can be used without adversely affecting the cloth was experimentally found to be relatively low. Consequently, the microwave irradiation would have to be applied for relatively long periods of time in order to achieve enhanced cleaning results. Even then, the degree of cleaning, whilst being better than that achieved through ordinary cleaning means, may not be much greater. The use of detergent would then be additionally needed in order to achieve the enhanced clean. The prior art therefore prescribes the use of detergent to achieve this.
The invention at least partially addresses the aforementioned limitations of the prior art.